5 Things That Happen to Your Mental Health When You Don't Get Enough Exercise

All the more reason to squeeze in a quick walk—even when you don’t feel like it.

You know by now that regular physical activity—from vigorous vacuuming to formal spin classes—is essential for staying strong and nimble, and for preventing injury and disease. But exercise is also hugely beneficial for brain health and mood management. In fact, exercising in some way every day is one of the most vital ways to stay cognitively fit in the short and long term. And research shows that regular exercise is positively associated with improved mental health, namely lower anxiety and depression. According to Celina Nadelman, M.D., a board-certified cytopathologist and fine needle specialist, even 30 minutes of exercise a day improves thinking skills, information processing, brain cell growth and resilience, stress management, memory, academic performance, and can help prevent or manage mental illness and neurodegenerative disorders. (That's a lot of bang for a half-hour of your time!)

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But it works both ways: If exercise can improve what you've got, lack of exercise can contribute to a mental health downturn. In fact, just 10 days without fitness can cause our brains to start losing cognitive function, says Dr. Nadelman. Then there's this particularly unhelpful catch-22: When mood is low (or stress is high), motivation to move is often low too—yet if you don't move, your mood could suffer even more.

While it's completely normal (even expected) to feel stagnant and uninspired to sweat when you're anxious, foggy, stressed, or depressed, the truth is, it's more essential than ever to stay active in difficult times. What can happen to your mental health when you're too sedentary? Experts explain how lack of movement can negatively impact our brains—and why it's so important for both mind and mood to squeeze in a brisk walk, quick sweat, or other physical activity every day.

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Our brains have a higher risk of anxiety and depression.

According to Katy Firsin, N.D., MPST, a naturopathic physician, when we exercise, the body releases feel-good chemicals, like anandamide and endocannabinoids, directly to our brain. These compounds not only block out pain receptors, but increase feelings of joy, she says. When we have a deficiency in these important chemicals, we tend to feel more anxious and depressed. "These chemicals also have an effect on pain, and there's a direct link between the aches and pains that come from being sedentary and our mental health," Firsin adds.

To fight against this phenomenon, you don't have to spend hours running on a treadmill. Firsin says it's enough to track your steps: Make sure you get up and move frequently by using a standing desk and going for walks.

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Our brains have trouble seeing the bright side.

If you're struggling to find the silver lining and keep jumping to the worst-case scenario, a lack of activity could be to blame. Exercise helps take the edge off and provides an outlet for us to release negative emotions, explains psychologist Yvonne Thomas, PhD. "Whether it's through cardio-related physical activities or more mild, less intense movement like walking or doing housework, a person is able to literally work out some emotions by breathing more deeply and by actively re-channeling emotions through one's body movements," she says. "It can set off the feel-good endorphins that can be calming and relaxing."

When we sit on the sofa all afternoon or bail on a yoga class with a friend, those not-so-great emotions fester and intensify, creating a cycle of Debbie Downer thinking.

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Our brains struggle to solve problems.

Think about the last time you ran into a roadblock at work that you had to navigate. Did you get stuck trying to brainstorm solutions, or could you think clearly and creatively and recall past situations for guidance? If you found yourself more on the struggle than the success bus, it could be due to lack of exercise. As Dr. Nadelman explains, physical activity improves our cognitive functions, from attention span, academic performance, and problem-solving to memory and information-processing speed. It also helps us remain flexible while multitasking and decision-making.

"Physical activity improves cognitive functioning via neuroplasticity, as well as increased synthesis and expression of neuropeptides and hormones," Dr. Nadelman says. "These substances help with neuroplasticity and neuronal repair."

Without even low-impact fitness, our brain can feel sluggish and tired, making it difficult to muster up motivation or deliver on responsibilities and deadlines. The next time you feel as if your day is dragging, consider doing a quick cardio workout for 15 minutes. In addition to long-term wellness, the burst alone will perk you up.

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Our brains develop self-deprecating thought patterns.

You know that moment of euphoria following a super-sweaty, challenging workout? You feel strong, unbeatable and excited for your recovery snack or meal. No matter what type of movement, Thomas says fitness boosts confidence and offers a sense of accomplishment. On the other end of the spectrum, not exercising has the opposite impact, decreasing self-esteem and image. "This is because the person who's too sedentary can feel and think of themselves [negatively] in many ways," Thomas says. "The person may feel less vibrant, fun, productive, energetic, and so on."

Once these thoughts begin, they're tough to beat. It becomes a cycle of putting ourselves down, not having enough energy to work out, and then feeling worse afterward.

05 of 05

Our brains can't manage stress as well.

In every stressful situation, we either have a flight or a fight reaction. If we're fliers, we flee, for fear of facing whatever trouble brews ahead. If we are fighters, we stick with it, sometimes becoming combative or defensive. Dr. Nadelman says this is an adaptive biological outcome that's not quite as helpful as it was in caveman days. Most of the time, people can find a happy medium between these two extremes and handle anxiety as it comes their way.

However, when we don't have a regular routine of physical activity, our brain releases the stress hormone, cortisol, making it trickier to manage our emotions effectively. "Modern-day stressors are usually not transient and increase cortisol in a sustained manner," she says. "This increase in cortisol has neurotoxic effects on the brain, which can damage the hippocampus by decreasing neuropeptide BDNF expression, and lead to depression." With aerobic exercise, we lower our neuroendocrine reactivity and reduce our biological response to stress, thus naturally feeling calmer and more in control.

The bottom Line? Much like you prioritize family time, work, and sleep, make physical activity a non-negotiable part of each day for optimal cognitive and emotional health—whether it's a yoga session, walk, bike ride, or cleaning out the garage. And if you don't have time for a full, formal workout, try committing to doing a tiny, three-minute workout every 30 minutes throughout the day to interrupt long periods of sitting.

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  2. de Sousa Fernandes MS, Ordônio TF, Santos GCJ, et al. Effects of physical exercise on neuroplasticity and brain function: a systematic review in human and animal studies. Neural Plast. 2020;2020:8856621. doi:10.1155/2020/8856621

  3. Britannica, Cortisol. Accessed June 5, 2022.

  4. Qin DD, Rizak J, Feng XL, et al. Prolonged secretion of cortisol as a possible mechanism underlying stress and depressive behaviour. Sci Rep. 2016;6:30187. doi:10.1038/srep30187

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